Automatic weighing-machine.



PATENTED MAY 16, 1905.

A. L. F. MITCHELL.

AUTOMATIC WEIGHING MACHINE,

APPLIUATION FILED MAY 19, 1903.

UNITED STATES Patented May 16, 1905.

PATENT OEEIcE.

ALBION L. F. MITCHELL, OF BOSTON, MASSAOHUSETTS, ASSIGNOR OF ONE-HALF TO(1. W. AIKEN, OF EAST ORANGE, N Ell JERSEY.

AUTOMATIC WEIGHING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 790,146, dated May 16,1905.

Application filed May 19, 1908. Serial No. 157,790.

To (all whom/ 117; rib/t7 RON/(387721.

Beitknown. that 1, Annie): L. F. MITCHELL, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Automatic eighing-Machines, of which the following is aspecification.

This invention relates to weighing-machines in which the weighing isautomatically performed, so that when one of the buckets or receptaclesof the machine has received a predetermined quantity of material from achute the feed of the material is automaticallystopped and the fullbucket discharged.

One of the objects of the present invention is to provide a means fordisposing of dust in the weighing of powdered material and insure theproper feeding of the material into the buckets or receptacles of themachine.

A further object of the invention is to improve the general constructionand operation of the machine, as more fully hereinafter set forth.

Of the accompanying drawings, Figure 1 represents a vertical sectionalview of an automatic weighing-niacinne embodying my improven'ients. Fig.2- represents a detail side elevation. of one of the buckets. Fig. 3represents an elevation of the upper part of the chute. Fig. 4represents a section on line 4 4 of Fig. 3. Fig. 5 represents a detailsectional view of one of the guards for the pivots of the weight-levers.Fig. 6 represents a section on line 6 6 of Fig. 5. Fig. 7 represents aperspective view of the pivoted spouts and holder.

The same reference characters indicate the same parts in all thefigures.

The machine illustrated. in the drawings is of the same type as theweighing-machine forming the subject of a patent granted to me July 23,1901, No. 679,154 and the main features of the machine need therefore bedescribed only in a general way.

10 is a frame having pivots for a beam 11, on which two buckets 12 12are pivotally suspended. On the two ends of the beam are pivotedtriocatchcs 13 13, which reside alternately underneath two weight-levers14:

14, pivoted between the side arms of the frame, said. catches and levershaving, re spcctively, knife-edge hardened plates 15 16. l Vhen theright-hand bucket is down and the left-hand bucket up, as shown in Fig.1, the left-hand bucket is filling and the right-hand bucket hasdischarged at previous load. .As soon as the left-hand bucket hasreceived its quantum it lifts the right-hand catch 13, the edge of whoseplate 15 escapes past the edge of the plate 16 of the right-handweighted lever. In order to make the rise of the inner ends of thelovers 1.4 as slight as possible, I drop the pivotal axes of said leversbelow the edges of the plates 1.6 a considerable distance, so that thesaid edges move on arcs at a considerable inclination to the paths ofthe edges of the plates 15 on catches 18. hen either end of the beam 11rises, the plates 15 16 will therefore quickly separate, the plate 15moving in an are opposite to that of the plate 16.

17 is a feed-chute having branches 18 18 discharging into the respectivebuckets, and 19 is a pivoted hollow switch or spout oscillated by themovements of the beam 11 through the arm 20 on said beam, having a pin21 engaging an arm 22 on the holder of the spout 19. The movements ofthis spout direct the stream of material into the one or the other ofthe branches 18.

Along the two sides of the chute 17 and extending along the outer sidesof the branches 18 are two air and dust ducts 2 23, whose lower endsterminate within the mouths of the buckets 12 alongside of the orificesof the chute branches 1S and whose upper ends are preferably connected,as shown, with pipes 24 24, returning into the hopper 25, from which thematerial is fed into the chute 17. The ducts 23 act as vents for thebuckets 12, allowing the air which is displaced from said buckets by theentrance of the material thereinto to escape, thereby allowing the material to feed evenly and with an unbroken stream into either bucket,and thus creating much. less dust than is ordinarily created. Such dustas arises from the material falling into the buckets passes up the ducts23 with the air and is directed into the hopper 25. Much greatercleanliness of the ma chine and surroundings and greater comfort to theoperative attending the machine are secured by this improvement than iscommonly secured with other weighing -ma'- chines. Moreover, thisconstruction enables the results named to be obtained without theemployment of a suction-fan or other means for producing an artificialdraft or exhaust.

The stem or delivery-pipe 26 of the hopper leads into a pipe-section 27,which is removably fitted to the top of the chute 17. The deflectingspout or switch 19 is removably mounted below this pipe-section in arectangular frame or-holder 28, by which construction I am enabled toremove the spoutfor cleaning purposes or access to the branches of thechute. This holder is provided with knife-edge trunnions 29, supportedon hardened plates 30, which are slidingly fitted in guides 31, formedon the sides of the chute 17 Above the plates 30 plates 32 are removablymounted in said guides, and together with the plates 30 they serve tosubstantially close the sides of the chute 17 where the trunnions 29pass through, thereby preventing the escape of dust.

33 represents closers or pivoted bottoms, hinged at 34 to the sides ofthe buckets 12, each closer being nfoved to closed position by gravityand locked by a latching-arm 35 in conjunction with a locking portion 36on a latch-plate 37, fixed to the side of the bucket, the latching-armbeing moved into closed position as the bucket rises by a stationary pinor abutment 38 engaging its upper side. As the bucket descends with afull load a second stationary pin or abutment 39 raises the latching-arm35, and the free end of said arm rides up an incline 40 on thelatching-plate. As thus far described the locking mechanism for theclosers is constructed as described in my aforesaid patent; but I hereinprovide a guard 41, formed on the latching-plate 37 and located aboveand substantially parallel to the incline 40, the purpose of said guardbeing to prevent the latching-arm 35 from being thrown back too far onits pivot when the bucket descends and said arm is released from thelocking-shoulder 36'. The plate 37 is formed with a slot 47, occupied byscrews ,48 48, mounted in a supporting-plate 49 on the side of thebucket, whereby the plate 37 may be adjusted and the relation of thelockin -shoulder 36 to the latch-arm 35 varied. n Fig. 2, 340 representsa portion of a steadying or guiding lever similar to that shown at i inFig. 4 of my aforesaid patent. This lever 340 is notched at its end, thenotch fitting aproj ectingportion of the pin, onwhich the closer 33 ishinged at 34.

The weighted levers 14 are fixed to rods 42, whose ends are formed withknife-edge trunnions 43 43, supported in studs 44 44,

which are mounted in the side arms of the frame 10. To prevent saidtrunnions from jarring out of their seats 44, I provide guardfingers 45,overlying the said trunnions and pivotally secured to the frame-arms byscrews 46, which may be turned to frictionally hold the guard-fingers,but which may be loosened to allow said guard-fingers to be thrown upout of position to release the trunnions and allow the weighted leversto be removed.

I claim 1. A weighing-machine including in its construction a movableweighing-receptacle, means for weighing said receptacle and itscontents, a feed-chute, and a duct having its lower end within the mouthof the receptacle and constituting an air and dust vent for saidreceptacle, the said receptacle being movable independently of the ductwhereby the sillciency of the weighing-machine will not be impaired bythe presence of said duct.

2. A weighing-machine including in its construction aweighing-receptacle, a feeding-channel delivering thereto, means forweighing said receptacle and its contents, and an air and dust ductleading from within the mouth of said receptacle back into said channel,the said rece tacle being movable independently of the uct whereby theefficiency of the weighing-machine will not be impaired by the presenceof said duct.

3. In a weighing-machine, a pivoted scalebeam, a bucket supportedthereby, a triplatch pivoted to said beam, and a pivoted weight-leverengaging said latch and having its pivotal axis located a substantialdistance below the trip-engaging portion of said lever, the ivots ofsaid beam and lever being relative y positioned to cause the engagingportions of the latch and lever to move in opposite arcs.

4. In a weighing-machine, a pair of weighing-receptacles, a chute havingoutlets to said receptacles, a pivoted annular spoutholder, and adeflecting-spout removably supported in said holder and adapted todeilect the material alternately into saidoutets.

5. In a weighing-machine, a pair of weighing-receptacles, a chute havingoutlets to said receptacles, a deflecting-spout adapted to direct thematerial alternately into said outlets and having a trunnion extendingthrough the wall of said chute, and a pair of removable plates mountedon said wall and located respectively above and below said trunnion.

6. In a weighing-machine, a rising and falling bucket, a closer pivotedthereto and having a pivoted latching member, a cooperating latchingelement on the bucket, an incline above said latching element,stationary means to actuate said member, and an inclined guard locatedopposite and substana pivoted weight-lever cooperating with said beamand having a trunnion, a trunnionseat, and a pivoted guard having itsfree end extending over said trunnion to hold it in its seat, meansbeing provided for frictionally holding said guard against turning onits pivot.

In testimony whereof I have aflixed my signature in presence of twowitnesses.

ALBION L. F. MITCHELL. Witnesses C. F. BROWN, A. D. HARuIsoN.

